Update this repo for DW_2000Q_6 decommissioning

[JoelPasvolsky]

Following the notification from March, in two weeks the DW_2000Q_6 will be decommissioned. Some of the examples in this repo, for example this code, should be updated.

[randomir]

Also:

simple-ocean-programs/Exploring_Pegasus/clique_embedding.py

Line 48 in a497053

dwave_sampler_chimera = DWaveSampler(solver={'topology__type': 'chimera'})

in addition to Joel's link above:

simple-ocean-programs/Exploring_Pegasus/biclique_embedding.py

Line 57 in a497053

dwave_sampler_chimera = DWaveSampler(solver={'topology__type': 'chimera'})

[randomir]

Ran into this issue again.

@vgoliber, would you like to fix this, or would prefer we do it?